<?php

// +----------------------------------------------------------------------

// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]

// +----------------------------------------------------------------------

// | Copyright (c) 2006-2013 http://thinkphp.cn All rights reserved.

// +----------------------------------------------------------------------

// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )

// +----------------------------------------------------------------------

// | Author: liu21st <liu21st@gmail.com>

// +----------------------------------------------------------------------

namespace Behavior;

use Think\Storage;

/**

 * 系统行为扩展：静态缓存读取

 */

class ReadHtmlCacheBehavior {

    // 行为扩展的执行入口必须是run

    public function run(&$params){

        // 开启静态缓存

        if(IS_GET && C('HTML_CACHE_ON'))  {

            $cacheTime = $this->requireHtmlCache();

            if( false !== $cacheTime && $this->checkHTMLCache(HTML_FILE_NAME,$cacheTime)) { //静态页面有效

                // 读取静态页面输出

                echo Storage::read(HTML_FILE_NAME,'html');

                exit();

            }

        }

    }



    // 判断是否需要静态缓存

    static private function requireHtmlCache() {

        // 分析当前的静态规则

         $htmls = C('HTML_CACHE_RULES'); // 读取静态规则

         if(!empty($htmls)) {

            $htmls = array_change_key_case($htmls);

            // 静态规则文件定义格式 actionName=>array('静态规则','缓存时间','附加规则')

            // 'read'=>array('{id},{name}',60,'md5') 必须保证静态规则的唯一性 和 可判断性

            // 检测静态规则

            $controllerName = strtolower(CONTROLLER_NAME);

            $actionName     = strtolower(ACTION_NAME);

            if(isset($htmls[$controllerName.':'.$actionName])) {

                $html   =   $htmls[$controllerName.':'.$actionName];   // 某个控制器的操作的静态规则

            }elseif(isset($htmls[$controllerName.':'])){// 某个控制器的静态规则

                $html   =   $htmls[$controllerName.':'];

            }elseif(isset($htmls[$actionName])){

                $html   =   $htmls[$actionName]; // 所有操作的静态规则

            }elseif(isset($htmls['*'])){

                $html   =   $htmls['*']; // 全局静态规则

            }

            if(!empty($html)) {

                // 解读静态规则

                $rule   = is_array($html)?$html[0]:$html;

                // 以$_开头的系统变量

                $callback = function($match){ 

                    switch($match[1]){

                        case '_GET':        $var = $_GET[$match[2]]; break;

                        case '_POST':       $var = $_POST[$match[2]]; break;

                        case '_REQUEST':    $var = $_REQUEST[$match[2]]; break;

                        case '_SERVER':     $var = $_SERVER[$match[2]]; break;

                        case '_SESSION':    $var = $_SESSION[$match[2]]; break;

                        case '_COOKIE':     $var = $_COOKIE[$match[2]]; break;

                    }

                    return (count($match) == 4) ? $match[3]($var) : $var;

                };

                $rule     = preg_replace_callback('/{\$(_\w+)\.(\w+)(?:\|(\w+))?}/', $callback, $rule);

                // {ID|FUN} GET变量的简写

                $rule     = preg_replace_callback('/{(\w+)\|(\w+)}/', function($match){return $match[2]($_GET[$match[1]]);}, $rule);

                $rule     = preg_replace_callback('/{(\w+)}/', function($match){return $_GET[$match[1]];}, $rule);

                // 特殊系统变量

                $rule   = str_ireplace(

                    array('{:controller}','{:action}','{:module}'),

                    array(CONTROLLER_NAME,ACTION_NAME,MODULE_NAME),

                    $rule);

                // {|FUN} 单独使用函数

                $rule  = preg_replace_callback('/{|(\w+)}/', function($match){return $match[1]();},$rule);

                $cacheTime  =   C('HTML_CACHE_TIME',null,60);

                if(is_array($html)){

                    if(!empty($html[2])) $rule    =   $html[2]($rule); // 应用附加函数

                    $cacheTime  =   isset($html[1])?$html[1]:$cacheTime; // 缓存有效期

                }else{

                    $cacheTime  =   $cacheTime;

                }

                

                // 当前缓存文件

                define('HTML_FILE_NAME',HTML_PATH . $rule.C('HTML_FILE_SUFFIX',null,'.html'));

                return $cacheTime;

            }

        }

        // 无需缓存

        return false;

    }



    /**

     * 检查静态HTML文件是否有效

     * 如果无效需要重新更新

     * @access public

     * @param string $cacheFile  静态文件名

     * @param integer $cacheTime  缓存有效期

     * @return boolean

     */

    static public function checkHTMLCache($cacheFile='',$cacheTime='') {

        if(!is_file($cacheFile)){

            return false;

        }elseif (filemtime(\Think\Think::instance('Think\View')->parseTemplate()) > Storage::get($cacheFile,'mtime','html')) {

            // 模板文件如果更新静态文件需要更新

            return false;

        }elseif(!is_numeric($cacheTime) && function_exists($cacheTime)){

            return $cacheTime($cacheFile);

        }elseif ($cacheTime != 0 && NOW_TIME > Storage::get($cacheFile,'mtime','html')+$cacheTime) {

            // 文件是否在有效期

            return false;

        }

        //静态文件有效

        return true;

    }



}